Conventionally, there is some demand for a reduction in power consumption in display devices such as liquid crystal display devices. Accordingly, for example, Patent Document 1 discloses a display device drive method in which a scanning period (also called a refresh period) T1, in which screen refresh is performed by scanning gate lines of a liquid crystal display device, is followed by a pause period (no-refresh period) T2, in which the refresh is paused by stopping the scanning of all of the gate lines. For example, it is possible to make settings such that control signals are not provided to a gate driver and/or a source driver during the pause period T2. As a result, it is possible to pause the operation of the gate driver and/or the operation of the source driver, resulting in reduced power consumption. The drive performed with the refresh period followed by the no-refresh period, as in the drive method described in Patent Document 1, is called, for example, “pause drive”. Note that pause drive is also called “low-frequency drive” or “intermittent drive”. The pause drive as above is suitable for displaying still images. Besides Patent Document 1, for example, Patent Documents 2 to 5 disclose inventions relevant to pause drive.
Furthermore, as a technology to reduce power consumption, the CABC (Content Adaptive Brightness Control) function is known in which the backlight intensity of a display device, such as a liquid crystal display device, provided with a backlight is changed in accordance with the brightness of an image to be displayed on the screen of its display portion (also simply referred to below as an “image to be displayed”). In the CABC function, for example, the backlight intensity is controlled in accordance with a pulse-width modulation signal outputted by a display control circuit in the liquid crystal display device. The backlight intensity is determined by the duty cycle of the pulse-width modulation signal. That is, in such a liquid crystal display device with the CABC function, the image to be displayed and the backlight intensity (the duty cycle of the pulse-width modulation signal) are correlated with each other. In the following, the value of the duty cycle of the pulse-width modulation signal is denoted by the symbol “DR”. For example, in the case where a dark image is displayed, with the CABC function, which correlates the image to be displayed and the backlight intensity, it is possible to set the backlight intensity low, resulting in low backlight power consumption. Note that the CABC function is effected (i.e., on), for example, when an image darker than a certain brightness level is displayed.